Sorry, just seeing this. I have a nice thread on some of the fun tweaks and toys available for the N900. Lots of info, some of it's a little old, but a good place for a "noob" to start.

The best kernel right now I'd say is either K46 (the last Titan kernel) or K48 (the last stable Pali kernel). K49 is nice, but it's still got a few glitches going on. K46 is rock solid, and far better than the stock Nokia kernel. K48 has lots of new tweaks, much better integration with h.e.n. and CSSU, and is relatively solid.

The only down-side of K48 vs K46 I've seen is that it does change something in the power management, so that some devices that used to run on the ultra-low voltage profiles no longer are stable with them. Frankly, I'd steer clear of trying to do excessive under-voltage anyway. The minor power savings doesn't seem worth the instability and the chance of data corruption on the device.

PS: I love that you're showing how this place should work. Lots of newbies come here demanding support or being rude. Most wind up getting very little because of their attitude. You came in asking politely and got tons of help rather quickly. It helps that you're clearly searching for info on your own too. Also, don't forget to thank people that help you! (Thanks button is lower right of each post!)